About the word "titrate"?

one time my friends and i were playing riddle games. One of my friends was giving a riddle that was hard to solve. And my other friend asked if he can "titrate" it with other clues. Now I never heard of that word except for chemistry cl. But not in this context. But from how my friend used it, I totally got what she meant. Now i wanna ask if that word is really existent in such context that she used it in other than in science cles. Does anyone know? Because I searched in dictionary.com and the only definition it gave me was the chemistry definition. So now i wonder if my friend just picked that word up from old chemistry lessons making it equal with the properties of the riddle game that we were doing. She has some adept vocabulary skills so I was guessing that such skills enables one to borrow from other sources even if they are not defined in the dictionary. Or maybe she just heard it from someone who used it in the same context, I dont know. So if anyone knows if that word is used like that, or if anyone else has used such word outside of a science context, you can let me know